Delivery of medicaments, nutrients, or other liquid substances into the subcutaneous tissue of a patient is known to be an effective treatment technique for various medical conditions. Subcutaneous liquid administration may result in a more effective delivery of a substance into the circulatory system than other administration techniques (e.g., digestive tract, respiratory tract, etc.).
Subcutaneous delivery is often performed with an infusion pump. An infusion pump is typically a portable device carried by the patient that contains a medicament reservoir and drive components for delivering the medicament into the patient. Infusion pumps can deliver medicament in a more precise and controlled manner than can be accomplished with manual delivery by a patient or medical personnel. Infusion pumps are generally one of two types. The first type includes a standalone pump unit worn by a patient at a location remote from the delivery site (e.g., on a belt). The standalone pump unit pumps medicament from the reservoir through tubing to an infusion set attached to the patient's skin and accessing the subcutaneous tissue (e.g., via a flexible cannula). The second type is generally referred to as a “patch pump” and incorporates the medicament reservoir, drive components, and cannula all in a single unit adhered to the patient's skin. In some situations, infusion pumps deliver a continuous flow of medicament into a patient (sometimes called a basal dose). Infusion pumps can also deliver intermittent doses, in some cases controlled by the patient (sometimes called a bolus dose).
Given that subcutaneous medicament administration is typically performed with liquid substances, most infusion pump development has been for the treatment of medical conditions for which a liquid formulation medicament is therapeutically viable. The most prominent example is the use of infusion pumps for the subcutaneous delivery of insulin to patients with diabetes.
The most common medicament for the treatment of Parkinson's Disease is the drug levodopa, which is often administered in combination with the drug carbidopa. To date, therapeutic formulations of levodopa/carbidopa have only been available in solid or powder form and are typically administered with an oral pill or an inhaler product.
Recently, the Applicant has developed the first ever liquid formulation of levodopa/carbidopa having a therapeutic concentration appropriate for delivery to the subcutaneous tissue (described in greater detail in U.S. Patent Application Publication Nos. 2013/0253056 and 2014/0051755, which are incorporated by reference herein in their entireties). This discovery makes it practical, for the first time, to develop an infusion pump device for use by patients with Parkinson's Disease and other CNS disorders.
Individuals with Parkinson's Disease and other CNS disorders exhibit different symptoms than individuals with diabetes. In addition, the drug dosage volumes are different for different conditions. Thus, currently available infusion pumps designed for the treatment of diabetes or other conditions are often inappropriate and ineffective for the treatment of Parkinson's Disease. Accordingly, a need exists for a new drug delivery device appropriate for use by individuals with Parkinson's Disease or other CNS disorders.